1. Field
The following description relates to a power semiconductor device having a field plate plug. The following description also relates to a method for manufacturing such a power semiconductor device.
2. Description of Related Art
Switching devices with a high switching frequency and a low power loss have been widely used in power conversion and power control circuits. There are various types of double-diffused metal-oxide semiconductor (DMOS) transistors commonly used as such switching devices. For example, there are a vertical double-diffused metal oxide semiconductor (VDMOS), which is a vertical type of DMOS, and a lateral double-diffused metal oxide semiconductor (LDMOS) which is a lateral type of DMOS.
The LDMOS has been widely used as a switching device for control, logic, and power applications. The LDMOS may have a high breakdown voltage (BV) to be able to withstand a high voltage, and a low on-resistance to be able to minimize a conduction loss at the same time. Therefore, researches into a reduced surface field (RESURF) structure that reduces a peak electric field in a drain region in order to be able to have both the high breakdown voltage and the low on-resistance properties of a MOSFET have been conducted.
However, the existing RESURF technology has issues, in that a channel length formed between a gate electrode and a source electrode becomes long, and a separate device isolation layer, for example, an offset trench, such as an offset shallow trench isolation (STI) structure is additionally formed between the gate electrode and a drain electrode for the high breakdown voltage to make a process complicated.